Helicopter rotor actuation and control



Oct. 20, 1953 A Q PETERSON 2,655,997

* HELICOPTER ROTOR ACTUATION AND CONTROL Filed Feb. 24, 1949 5Sheets-Sheet 1 Oct. 20, 1953 A C, PETERSQN 2,655,997

HELICOPTER ROTOR ACTUATION AND CONTROL Filed Feb. 24, 1949 5Sheets-Sheet 2 Oct. 20, 1953 l A, C, PETERSON 2,655,997

HELICOPTER ROTOR ACTUATION AND CONTROL Filed Feb. 24, 1949 3Sheets-Sheet 3 Patented Oct. 20, 11953 UNITED GEF ICE.

Adolphefll.,r Peterson, Minneapolis.; Minut- ApplcastionFbruamM,1941);"SerialfloV 7 8,1385?" My invention.- relatesto-af-means-providingl forl sustentation and zloropulsion*for-4air-borneL-cra-ft; Wherefore it -isr called',V helicopter-` rotor4actuation= andi control;-

The chief objects` of myinvention are -toprovide al form.lof-sustentation andi propulsion means for' air-craft; whichmeansvshallembody especial?v advantages tlieuse thereofinJ thell'arger formV ofcraftzwherein sus-tentation is principally pro*HV videdfby rotors,andWl-ierein especially-there are advantages of strength and?simplicity/in: thefformr of" the'. incidence 4'varying means, which` is*utilized-i in; aircrafty ofil the.v helicopter type;y er i'nf lighter;thaznfair-craft' utilizing suchmeansas an anxili` iarysustentatibn-orlifting means-and propulsion means. Anf objectf of? thisl device-is theprovision of: anV eicientxandi'strong means fiorcontrollingI andvimparting 1 the cyclic -incidencexchange in'y theI blades ortwings ofalrotor for suchair-crait. lltlyi means ztor. incidence change provides"afmeans changing the incidenceI of" dual rotcrs-mountedi on- .asingle/axial sustaining or' slipper-tingfmeans',l and therebyfenablesefcient useof d'ual rotors-1 onf af single.- axis. Myrmeans-`provides anv efficient incidenceY changing.' means:` forl cyclicincidence changing,V as is. necessary: forv sustentation andipropulsion'. ini combination4 fromarotor# means; andprovidesthisfmeansin avformSw-hichis simple and .reliablefiniuseaandi strong initsiactiongsand as isfespecially/` adapted: for use f asI a durable'meansftherefore.l Mair-craft: of tl'ie':-liel'i'copterfy W136- '01semifhelicopterf type.1 and; Whi'clfi'frnayf be mountedr in'. multiple;number on suchB airecrafii to provide for: sustentatiomandipropulsionwtherebyf offfrela1r tively:v large;` weights; andi 'thereforewould' b'ef'fes'f' pecially suitable: 'for'4 large-Spassengerf carry-ingCraft-or freight carrying craft... An= object'isdzlie` provisionconnection therewithl of efficient*` means fonyarying theidirection of'the propulsion` eiefzted by any: one unit .ofl suchmeans.

'1l-hex principal devices land combinations* ode vicesfcomprisingmy*invention'.Y are' as h'ereinafteiY described `and` as denedin'theclaims.Intlie accompanying drawings Which;i'llustratezmy in vention,myYdevice;is'.;sl1own` as za: unitfwhich= may be. mountedmanyfnumberfthereofaas'finz multiple: number on anair-craft,andyisfturthen slmwn'aiszA mounted. onfsuchiair-craft; Likevcharacters ,refer tolike parts throughout. the severalviewsz;

Referring to the drawings`:,.

Figure-l is aiviewzimverticalisection;om arli'ne and.- planeipassingvertically" throughrthe; axisfof: rotation,of:oneof my units;Zandjsa'theregshown: relation: to a1 portionof an: air-craft ,Wi'ng orbeamorfmounting:` by. Whichr it. is1mountedson ,am

l ceptFigures 213i 3i and; 51Wliichrare-on the same'l scale. i

Eigurez: i'saalhori'zontall section' at'flright. a-ifisggles' tor-tideIse'cticm ofi Figure l, this'.y section beingon the kline ZLZiot':FigureA12; andi is 1 chieiiy al detailf lcokingfupwardlyat .partofftlie'fcperating*mechanisnr;oitone ofthe two rctorsi Eigure 351s.adetailchieflyffin 'verticali sectiong on the line 3 3 of Figurelfsl'lmningffafzcrosS sec tionY atright: angles tot the: plana of 1 Fig;1i; the

' eccentric; and? :linkingfrmeansoi-"S they other rotor' ofathedevice-fy Figure lrfisfa.dagrammaticaviewshowing twoofstherv.rotorunitsacliz incliidingff. two eppositel'yIrotaztingfrotorsY-in connectionL witlran associated power:orxsenginef.drivingameansfforthe' pairf off rotors,the-aircrattconstruction not being-shownexcept.diagrammaticallyrfbyzasmall section ofi' supportingzstructureast.; each rotor unit"i Eigureff-is ai detaili diagrammatic'sketch-showthei-v relative a incidence; positions of blades -etf theeAteva; rotors off.: a,..uni;', innone; phase of* their mmzemenjr.:

Figure; fi'fisaz front'vieW-fof' ansairecraft4 embmiyL ings-inritsconstrnctionftwofof my rotor units @for A sustentatio'n .1 propulsion;the units:r beingl shawnion;asmalllscale a-ndffonly. diagramma-titcallytogetlier witlbthe controlwheelffor the two rotors, as1slrdwnlzby:.dottedi lines;

unt visible from the one side of theiair-craftf FignreiSr-:isafdagrammatic sketch showing-the relation.: of:V propulsion; ofi-thefblades in. normali'- action;`

FgnrefiQais-.ancthen diagrammatic sketch' show@- ing the, relatierrV`of\ propulsion `exerted:k by blades o .therotor units vin another.relation 'et -contmol4 Figure, 10 shows aamodied formiot mounting:ofliny rotor units. on an..air.craft, afore--andaft relation.-

Fig". Il" shows a modified formflmountingbt rotoriunitson an air-craft.

F'gz 1-2 showsa modiedlmeansof control for the. adiustment' means` of -arotor' uniti Itshouldibe notedl'rstthat T contemplate that myrrotor:unit means may `bef-rnounted inanyA number of-` unit'supon'- anairecralt for `4its sustentation4 and: propulsion; -andil? pref'erl thatit v bev` mountefb:ixn such`= `numbersrasl three orV four or ,3 more lonaant air-cram as :greater-stability and reliability of the air-craft isprovided by the greater number of units. I describe the rotor unit rstas it may be mounted in any number, multiple or otherwise, upon anair-craft.

Referring to Figures 1, 2, 3, and 5 for the description of the novelrotor unit, the numeral I5 indicates, in these figures, a small sectionor portion of the associated air-craft structure or pylon mountingtherein, for support of my rotor unit or one of such rotor units. Thispylon mounting structure I5 is so strongly constructed that it willserve as a mounting for the revolvable rotors of a propulsion or rotorunit, which consists in the main of two blade or wing rotors, one ofwhich is generally denoted A and the other of which is generally denotedB. The rotor A is an upper rotor and the rotor B is a lower rotor, andeach of these is mounted on the same axis as its axis of rotation. Eachrotor is comprised generally of two blades ofthe airfoil type or Wingtype, as shown, and has associated with it cyclic pitch control oroperating means for the pair of blades, and each blade has a sectionsuch as shown in Fig. 5, or any form which will most efficiently andadequately perform the work of sustentation and propulsion as hereafterdescribed. The rotor A has two blades each denoted IS, and the rotor Bhas two blades, each denoted Il. The blades of either rotor may beeither more or less than two in number, and may in some constructions:be as many as four or more, the construction being modied accordinglyfor that purpose.

The pylon mounting I5 has fixed on it a vertical static bearing iixtureI8 and this bearing fixture I8 may be considered as one section of thepylon mounting. The static bearing fixture may be cylindrical in part orall in form and is very strong and supports within it by any means asusually employed a pair of roller bearings I9 (or ball bearings), thesebearings being axially concentric, that axis being vertical, normally inaction. 'I'he pair of bearings I9 support concentrically with bearingfixture I8 an outer rotating sleeve or cylindrical shaft 2Q and aconcentric sleeve or cylindrical shaft 2l, and concentrically withinshafts and ZI a normally stationary but rotatably adjustable controlshaft 22. The inner rotatable shaft 2I is rotatably mounted by a pair ofroller bearings 23 and 24, respectively, one at the lower end of shaft2li and the other at the upper end of shaft 20. The stationary andadjustable shaft 22 is mounted by small roller bearings 25 and 26,respectively, one at the lower end of shaft 2| and the other at theupper end of shaft 2|.

The shaft 20 has formed or fixed on its lower end a spur gear 2l and theupper face of the latter forms a surface for rotation of the Verticalthrust ball or roller bearing 23 for vertical thrust bearing between thespur gear 21 and the lower face or end of the fixed sleeve I8 andthereby between the shaft Zl and the sleeve I8. The shaft 2I has formedon its lower end a spur gear 22 and the upper end of the latter forms asurface for rotation of the vertical thrust ball or roller bearing Si!for vertical thrust bearing between the spur gear 2Q and the lower faceof the spur gear 21 and thereby between the lower end of shaft 2I andthe spur gear 27 and through bearing 28 between shaft and xed sleeve I8.These means thereby support the shafts 20 and 2I for concentric rotationand for vertical thrust or lift `against the xed bearing fixture I8 andd thereby for vertical thrust or lift against the pylori mounting I5.

The upper end of the shaft 20 bears formed or xed thereon a concentricdrum 3l which has two horizontally disposed bearings 32, formed thereinand equally spaced radially thereabout, each of these bearings 32supporting oscillably therein one of the oscillable horizontal axles 33,of which there are two. Each of the blade axles 33, has an interiorfixed or integral shoulder orriiange 3d which absorbs radial orcentrifugally outward pull of the associated blade in rotation, of therotor. Each of the blade axles 33, has exteriorly of drum BI an integralor fixed bevel gear 35 which is a so-called pitch control gear orelement, and has also formed therewith and assembled therewithexteriorly of the bevel gear 35 a universal joint 35 for the airfoil orpropeller blade Il of the lower rotor B. The joint B of each blade Il ispreferably such that the blade II is fully articulated, that is suchthat the connections of the blades il to their axles 33 compriseiiapping and lead-lag pivots (the axes of which, either or both may beobliquely inclined in the known manner). The support of each blade issuch as to limit the inclination of the blade to the axis of itssupporting shaft in the rotor, so that there will not in action beinterference of the rotors, one with the other.

The upper end of the shaft 2I bears formed or fixed thereon a concentricdrum 3l' which'has two horizontally disposed bearings 38 formed thereinand equally spaced radially thereabout, each of these bearings 38supporting oscillably therein one of the two oscillable axles 39. Eachof the blade axles 39 has an interior fixed or integral shoulder flange4B which absorbs radial or centrifugally outward pull of the associatedblade in rotation, of the rotor. Each of the blade axles 39, hasexteriorly of the drum 3l, an integral or fixed crank-arm GI which is aso-called pitch control element, and has also formed therewith andassembled therewith exteriorly of the crank arm QI a universal joint Q2for the associated airfoil blade or propeller blade I6 of the rotor A.The joint cl2 of each blade I 6 is preferably such that the blade I6 isfully articulated, that is such that the connections of the blades I6 totheir axles 39 comprise flapping and leadlag pivots (the axes of which,either or both, may be obliquely inclined in the known manner), but theconnection is also such that the blade is limited in its inclination tothe axis of its shaft so that the blade may not become so much inclinedas to interfere with action of the other rotor. It is contemplated thatthe blades of each unit, as described, may be fully articulated, orpartly articulated, to swing in either or both planes, or it may be xedfirmly to its blade axle 33 or 39, as the case may be, and that theseconnections, are preferably such that the blades in rotation willoperate as blades of rotary blade or wing sustentated air-craft, usuallyoperate, and that they may be so fixed, to their said axles, in anymanner which may prove most suitable for any particular construction,and in accordance with the specific design and its desiredcharacteristics in flight, and that this may be in accordance with anyknown construction of rotors for such purpose.

The bevel gear 35 of each blade I 'i is in permanent cooperation with anassociated one of two bevel gears d3, and each of the latter isoscillably mounted by a short shaft M in a bearing iixed on orintegrally formed with the drum 3|,

andi each: shaft .44 :hason its @lower end. acranlc armf 46 whereby the'shaft 441andfbevel`. gear-:413i is oscillatedin timed relation. withtherotationi oi rotor B., through: one master link. 411. and the; connectedpivoted link. 41a, by. an.. eccentric. 48.; formed on a control: sleeve.49, thelatter being.' concentric with and-mounted exteriorlyf ofathebearing xture I8 as; abearing. TheA4 controL sl'eeve- 49 has formedonhitbeloweccentric. 48, a. sprocket wheel. 561, whereby the. sleevey49.. and with it the eccentricrrlmay loe-adjusted rotatably: oir thevaxis of shaft.v 2B`l by meansr of.' the. chainI 5|, the latter being incooperation at .itsfoppositef end with asmall. sprocket wheel? 521- The:sprocket wheel 5ly ison sha-ft 531, whichrbears bevel geary 54- at itslowerlend for the adjustment inunisonI with the other control means, ashereafterY d'e-f. scribed.

The-crank armdl# ofleacha axle: 3d is in peri/nanent cooperation throughone of the two. associ` l ated links 55 (eccentric straps)k with anassociated one of two eccentrics 56, each of which ison .theeXterior endof a shortV shaft 5i?, each of# the latter being oscillably mounted. inaY.bearingni (of two) formed in thedrum 3v?, the. shafts fait oscillatingon horizontalaxes, Each of. the twoy shafts 51 on itsv inner end-withinvdrum-3! bearsv xed thereon a bevelgea-rv 59 and each: ofthe twobevelgears. 59 isin.l permanent cooperation.

with one centrally disposed bevel gear-6|). which is fixedA ontheextreme upper end et control. shaft 22e. The. extreme lowerend ofvcontrol. shaft 22 bears fixed thereona sprocket wheeltl whereby throughsprocket chain. 62 and. sprocket wheel 63 on shaft. te, and'- bevel gear65A on shaft 54,Y the controlV shaft 22 is rotated.' in. unisonwithl andinexactly.y the same degree as the rotation or adjustment-ot sleeve:deL/by means ofa common bevel gearv St. which is. on vshaft 51 androtated or adjusted ley-means*` of turningof theadjustment elements.by.y thehand control? wheel 1|. The rotationI ofthe control. shaftA 22and the controlsleeve 4Q, is however, always. opposite. That is, theymay.' rotatevin either direction, through controli by hand wheel. 1|,but 4 alwaysthe'y move, as to. each other, infopposite directions, andaccordingly. their-attached eccentric 48, and bevel gear Sil, alwaysrotate. in op; posite directions, when. and.' if`tliey are rotated,l andtheir rotation is-uin. exactly'4 theI same. degree. or amount intheparticular: direction'. ofv rotation. The rotation ofthesecontrolmembers48 andt 60', is not more than through ninetyzdegrees, fromtheforward night. condition,` toi procure2 theuneutralized propulsion'vconditioner status, and through 180 degrees, from the forward flightcondition, tov procure the. rearward flighty com.. dition, but may bethrough varying degreesof.; such movement, either way.

'Ihespury gear 2li of rotary shaft` iiisiin-k per.- manent. cooperationwith thesmaller spur gear` 1&2, and the latter is. Xedon the uppenendfothe vertical drive'4 shaft T3 which: is rotatable.v in the ixed bearing7x4. inthe;v pylon mounting |5'.. The spurY gear 29 of. rotary shaft2|-` is4 in perma-v nent cooperationv with. the smaller spur. gear '15and the latter is xed on` theupper end'. ofV the vertical drive shaftr'B; which is rotatable inzthe xed bearing. Hin'. theV pylori mounting;L5.

Thetwo. vertical drive shafts. 13.,.and5. which I. illustrated as, 8.8.

" fuselage trol. shaft 67,.' and.' the Acontrol. wheel;V it.

shaft 1-80, the. latter being: rotatable.1 in; ixcd: bearing (notshown); .in the iuselage structure or its wing structure. The placing ofbevel gears.A of sets18 and 1.9; isV such thatithetwowerticalv drive.shafts |;3-Y and lffiiare driven. inlopposite direct-ions and thuszthe,rotary shafts; .21and2'|rv are. also always: driven opposite;directioir. and the direction. or drivingv is.. such as; to each, as.tov produce-A the propulsion effects. hereafter.` described; Theshafts.7:3 and 1.6 ,may be; mounted many auxiliary bearings.. not. shown.. as.ymay: be, necessary.

The, propeller.r shaft, amis, driven througln'theuniversal joint, 8|.and shat82iand engineer-,ank shaft'. |35 .through one-way clutch or.over-runningV means. 83. by.l the engine. 8B, whose, crankshaft' 85 is.always driven in oneA direction to.` cause; the. correct. propulsive.effects; of thefrotors: AandlB; The. engine. 86; mayI be. of any type,such as..inter:V

nal, combustion engineeor turbine. and it .iszsupa plied. with fuel'v bya` conduit 8.41.,.fromzaaoormnonf supply tank 8 1'. Thesupply of fuel'may beacontrolled. to increase. or diminish thea power and speed of theengine 86 by means. ora control' This control. may be. of; .any typewhichy will hestgaccomplish change. of. the,- powerfoutput. so that thecontrol e1`iects.as.-here;. after stated, may be achieved. By the.-control: of; the enginepower out-put, the4 driving; power andpropulsive. effect (which` may be. neutralized asY hereafter described-fand-lift eiect; off; the rotors A and B, may becontrolled, asnecessary.; to; giveincreasedj propulsionl and` litt efech. or onlylift, eiect proportionedto the power output, for the. propulsion oi theair-craft, or: the pro;m pulsion and climb: or only for climb eecir. as;hereafter described; While I have.V described.. this. change of, lifteffect as procuredby the; change-f of, engine power,l output, any othermeans-may be used, suchvasincreasing vor diminishing. of: the angle'ofincidence of rotor blades., to increase? the climb eiect..

Referring now to: Figures.- 6 and;- 7.,. wherein. the; roto-r unitsareshown asincorporated with an air;- craft structure, there arehere showntwo Suche rotor-units,v asl have described, each having twd rotors A andB, asabove described inzconnectiom with onev rotory unit, andr thesetwo; rotor units: are-mounted,onefat each endotawing structurel 2- whichis part of an. aircraftstructure havingf The air-craft structure: haswheel mountings 3;, landing wheeler li, these` being. the main weightcarrying.,wheels, sti-:feringv wheel. 5:' carried by pivotable mounting.6 observationu Window 1', rearwardly extending empennage 8,',1

f rear stabilizer wing EL, elevator lil;A pivotably -xed thereon andhaving anyl of the usual'controlz means, side aileronsA or control;wingsy i| (also,- controlled by any means, not shown) vertical.stabilizer l2, vertical rudder |13- (controlled.` as; usual, not shown).The` pylon mountings i-ot. the two. rotor units` AV and .,B,` are oneat. each; end of. wing structure'. It willbe; seenfinxiigura 6. thateach. ofthe two rotor units; which: be. designated Xand Ygeneral1y,havefthepcon-- of the; rotor units X. andv Y mayaceordingly be.separately-.controlled by the;,p ilot. Anymans. for` unifying this..control may be utilized.:l if. that, be found advisable;

Having describedl in detail-the.- constructi'on, of, the rotor unit (X.or.Y YL the operationof.y either; ofthel Arotor units is now'rstbriefly-described: The.- engine 85,01 the rotor unit may beipaced:in; operation; by any starting; means; ,(notshown;

and controlled by means 88. to start the Vshafts 13 and 'I6 in rotationin their oppositely rotating directions.

In operation, as rotary shaft 20 revolves, the master link li'l and theconnected pivoted link 1a are carried around eccentric 48 .wherebycranks @t of rotor B are reciprocated and thereby bevel gears 43 areoscillated and oscillate bevel gears 35 and thereby oscillate axles 33of blades i? so that blades EI are slightly oscillated, but suiciently,so that in the propulsive movements of blades i1, which will berearwardly of the aircraft for forward flight, the blades Il have agreater pitch angle than they have in the nonpropulsive phases of themovements or rotation, that is the phases during which a blade Il ismoving forwardly as compared with direction of flight, the blades willhave the lower angle of incidence. Thus pitch angle is deepened duringrearward movement of any blade in its cycle, as compared with theforward direction of flight, and the pitch angle is lessened during theforward movement of any blade in its cycle of rotation of the rotor B.

Likewise in rotation of rotor A, the pitch angle of blades i of rotor Aare given a cyclic change of pitch angle to produce the propulsiveeffect for forward direction of flight. In the case of rotor A therotation of drum 3? with its blades i6, causes bevel gears 59 to bepropelled around the periphery of level gear t0, which is stationary(except as adjustable) and this movement causes gears 59 with theirshafts 57 to turn continuousiy once for each rotation of drum 37 andthis rotation of shafts 5l causes eccentrics 56 to rotate withineccentric straps 55 once for each rotation of drum 3?, whereby thestraps are cyclically given a reciprocating movement which is impartedto cranks fil in the same cyclic phase as eccentrics 55 move, andthereby the axles @Si of blades it are oscillated as necessary toproduce the cyclic increasing of the pitch angle of any blade it. Phasesare such (as to each rotor A and B), as to produce the deepening ofpitch angle of any one blade of one rotor, as it moves on one side ofthe vertical axis of rotation, for either forward propulsive effects orfor the opposite direction of propulsion. The phases of deepestincidence of rotors A and B of the unit, may be simultaneously alteredfor the unit by means of the independent control wheel 1l, whereby thesleeve 4s and bevel gear 6E] are moved in opposite directions, forcontrol of the phase periods of the blades of the rotors A and B. Thehorizontal propulsion effect of the pair of rotors A and B of a unit Xor Y may be altered either for complete neutralization of propulsion(without impairing lift effect) or for change of direction of thepropulsion, in any unit X or Y. Propulsion effect may also beneutralized by making propulsion eifect horizontally, in oppositedirections transversely of the aircraft, as to the two rotor units X andY, by the control wheels I-'iL Or propulsive effect of one rotor unit Xmay be in direction, say forwardly, and that of unit Y in the otherdirection, say rearwardly, thereby producing a turning effect on theair-craft. The hand wheels 1 I--1I of the units X and Y are shown asindependently operable in order that the pilot may have complete controlin this manner, while at all times the lift effects are proportional tothe power output of the engines i5-86, within reasonable limits, Thewing structure 2 will provide some lift effect in forward night, and thecraft may be constructed as to always utilize this effect, assuming thatthe craft will always be operated from or to the usual landing strips,but the structure is not necessarily limited that way. The ailerons Iland rudder I3 and elevator IU may be utilized to assist in control ofthe air craft in flight, especially in ascending or descending, forguidance of the air craft in horizontal direction or vertical directionor for balancing of the air craft. The wing structure 2 may especiallybe used to assist in climbing effect, while the craft is forwardlypropelled by the rotor units X and Y.

Referring now to Figure 10, this figure shows a different placing ofrotor units X and Y on an air-craft, the said units being in this formplaced in the longitudinal axis of the fuselage, one forward and theother over the rear end of the air craft, each supported thereon as theunits are supported in the rst form shown. Each unit is separatelycontrolled as in the first case described.

Referring now to Figure l1, this figure shows a different placing ofrotors denoted respectively, X, X1, X2, X3, on an air-craft, the saidrotor units being in this form placed one fore and one aft along thelongitudinal axis of the aircraft, and the two others are placed at theends of a wing structure as in Figure 6 and at a location which is withregards to length of the aircraft, intermediately of the two other rotorunits X1 and X2. Thus this form has four rotor units. each having tworotors A and B, as in the first form described and each of the rotorunits is separately controlled as in the rst form described, or asdescribed in connection with Fig. 12, hereafter. By the separate controlof each of the four rotor units in this form, the pilot can achieve anydegree of control over the direction of travel of the craft and varyingdegrees of forward or rearward travel, without at any time altering thesustentation of the rotor units relative to the craft as a whole, and inthis manner stability in large air-craft is easily maintained, by thepilot in flight.

Referring to Figure l2, this figure shows a modified form of controlwhich may be used for each of the rotor units as employed in any of theforms of mounting of the rotor units on an air-craft. In this modifiedcontrol, the shafts 53 and 64 which individually adjust the positions ofthe elements t9-148 of one rotor and 22-60 of the other rotor, are eachindependently controlled by means of separate gears 66a and 65h engagingbevel gears 5d and 65, respectively, and the gears 65a and 661 areoperated by electric motors Se and et, respectively, so that the pilotmay by any electric switching means (not shown) cause either motor te or9@ to be operated in either direction for driving of the associatedshafts 53 and 64 in either direction, independently of the other. Inthis manner independent control of either the elements lis-d8 or element66, in a rotor unit, may be effectedand a more varied control of therotor unit may be eifected by the pilot, thus effecting a more greatlyvariable control of the propulsion by the rotor units.

The form of control shown in Figure 12 may be used in the rotor unitsfor any type of mounting of the rotor units on an air-craft, so that aneiiicient control is achieved, with such degree of stability in any typeof air-craft as is desired.

I contemplate that my form of rotor unit will preferably be used inmultiple number on an aircraft in order that stability will more readilybe achieved infiflightfof the :air-craft, :and iinbrder that.` :control:of fthe air-craft fcr..-Schange:of l the propulsion of .the'rotoriunits, horizontally, may be .effected more readily'zwithoutigeiiectnponthe stabilitycof `the air-craft rand also inorder that greatervariability of the climb effect may be achieved.

Jiviihile I lhave'ishown vmy device ina particular formand iuse, .Icontemplate that my device may be iconstructed fwith variation in itsdetails and with variation in its use,'without departure l.frein thespirit,andconternplation of my invention, and I especially Acontemplatethat application of the propulsive power of "an engine Yto therotors-fof a unit or units :may beeiectedin any manner, and Within thescope and contemplation ofmy invention.

What IcIaim is :1. :Infanfair-craft, a pylonmoun-ting having a staticAbearing fixture nxed therewith; a Viirst rotor hub unit mounted Yin thebearing nxture to rotate on a vertical axis and having air-foil bladeseach mounted -in the "rotor hub unit to have oscillation on anaxisfextending in the horizontallilanezas substantially a radius of thecircle aboutitheaxis of the rotor hub unit, each airfoil blade having abevel gear fixed therewith, the rotor hub unit having,T oscillatableshafts mounted substantially on vertical axes in the rotor hub unit,each oscillatable shaft having fixed thereon a bevel gear inter-engagedwith the bevel gear of an associated air-foil blade, each oscillatableshaft having a crank fixed thereon; a second rotor hub unit mounted inthe bearing fixture to rotate on an axis co-incidental with the axis ofthe first rotor hub unit, the second rotor hub unit having air-foilblades each mounted in the said second rotor hub unit to haveoscillation on an axis extending in the horizontal plane assubstantially a radius of the circle about the axis of the rotor hubunit, each air-foil blade of the second rotor hub unit having a crankfixed therewith radially of the axis of the oscillation of the air-foilblade, the second rotor hub unit having shafts oscillatably mountedtherein each on an axis substantially parallel to the axis ofoscillation of an associated one of the air-foil blades, each last namedoscillatable shaft having iixed thereon an eccentric and a bevel gearthe eccentric having inter-connection with the crank of the associatedair-foil blade by an eccentric link; a normally static control bevelgear fixed on the nylon mounting, the said control bevel gear havinginter-engagement with each of said bevel gears of said second rotor hubunit; a normally static control eccentric mounted on said bearingfixture, an eccentric strap rotatably mounted on said control eccentric,links spaced about the eccentric and connecting the eccentric strap witheach crank of said drst rotor hub unit; and means connected and forrotating the rotor hub units in opposite directions.

2. In an air-craft, a pylori mounting having a static bearing fixtureiixed therewith; a rst rotor hub unit mounted in the bearing xture torotate on a vertical axis and having air-foil blades each mounted in therotor hub unit to have oscillation on an axis extending in thehorizontal plane as substantially a radius of the circle about the axisof the rotor hub unit, each said air-foil blade having a bevel gearlixed therewith, the said rotor hub unit having oscillatable shaftsmounted substantially on vertical axes in the rotor hub unit, eachoscillatable shaft having fixed thereon a bevel gear inter-engaged withthe said :bevel gear offan associated air-'foil blade and eachioscillatable vshaft :having a crank xed thereon; a second'rotorlhubunit mounted in the bearing fixture to rotate on an-axis co-incidentalwith the iaxsof the first rotor hub unit, .the second rotor hub unithaving air-foil blades each mountedgin `the saidfsecond rotor hub unitto have oscillationnnianaxis extending iin' the horizontal plane as`substantiadly -a radiusof the circle about theaxisiof the rotorihubunit,-eachsaid air-foil blade -havingfa 4crank iixed vtherewith radiallyof the '-.axis `c'f ethe oscillation ofthe air-foil blade, the :said:second rotor hub :unit rhaving shafts cscillatablymounted*therein eachon an axis substantiallygparallel to'thefaxis of oscillation of 1anassociatedfair-.foil blade, leach xsaid last :named oscillatable shaftfhaving ii-xedethereon-an eccentricfand abevelgearzthe eccentric havinginterconnectioni'with the crank of 'thezassociated airfoil blade ,by aneccentric flink; a normallyistatic control bevel gear =iixed `on the`fpylon mounting, the :said f control bevel gear having inter-engagementwith yeach Vof said bevel gears Yofsaid second rotor hub unit; anormally static control eccentric mounted A,onsaidfbearingfixture, aneccentric strap .rotatably mounted on `said control eccentric, linksspaced about the eccentric and connecting the eccentric strap with eachcrank of said iirst rotor hub unit; the said control bevel gear havingrotatable mounting on an axis coincidental with the axis of the rotorhub units and having an adjusting element fixed therewith; the saidcontrol eccentric having rotatable mounting on said bearing fixture tobe rotatable on an axis izo-incidental with the axes of the rotor hubunits and having an adjusting element fixed therewith; and acoordinating control means connected for rotating the said control bevelgear and the said control eccentric in opposite directions.

3. In an air-craft, a pylon mounting having a static bearing xture fixedtherewith; a rst rotor hub unit mounted in the bearing fixture to rotateon a vertical axis and having air-foil blades each mounted in the rotorhub unit to have oscillation on an axis extending in the horizontalplane as substantially a radius of the circle about the axis of therotor hub unit, each said air-foil blade having a bevel gear fixedtherewith, the rotor hub unit having oscillatable shafts mountedsubstantially on vertical axes in the rotor hub unit. each oscillatableshaft having iixed thereon a bevel gear inter-engaged with the saidbevel gear of an associated air-foil blade and each oscillatable shafthaving a crank nxed thereon; a second rotor hub unit mounted in thebearing fixture to rotate on an axis co-incidental with the axis of therst rotor hub unit, the second rotor hub unit having air-foil bladeseach mounted in the said second rotor hub unit to have oscillation on anaxis extending in the horizontal plane as substantially a radius of thecircle about the axis of the rotor hub unit, each said air-foil bladehaving a crank xed therewith radially of the axis of the oscillation ofthe air-foil blade, the said second rotor hub unit having shaftsoscillatably mounted therein each on an axis substantially parallel tothe axis of oscillation of an associated air-foil blade, each saidlast-named oscillatable shaft having xed thereon an eccentric and abevel gear the eccentric having inter-` connection with the crank of theassociated airfoil blade by an eccentric link; a normally static controlbevel gear xed on the pylon mounting, the said control bevel gear havinginter-engagement with each of said bevel gears of said second rotor hubunit; a normally static control eccentric mounted on said bearingfixture, an eccentric strap rotatably mounted on said control eccentric,links spaced about the eccentric and connting the eccentric strap witheach crank of said rst rotor hub unit; the said control bevel gearhaving rotatable mounting on an axis coincidental With the axis of therotor hub units and having control adjusting means connected and incooperation therewith to rotate the controlV bevel gear; the controleccentric having rotatable mounting on said bearing xture to berotatable on an axis cio-incidental with the aXes of the rotor hub unitsand having control adjusting means connected and in cooperationtherewith to rotate the control eccentric.

4. All of the means as described and as claimed in claim 1 and incombination therewith; the said control bevel gear having rotatablemounting on an axis co-incidental with the axis of the rotor hub unitsand having an adjusting wheel rotatably fixed therewith; the saidcontrol eccentric having rotatable mounting on said bearing X- ture tobe rotatable on `an axis co-incidental with the axes Yof the rotor hubunits, and having an 12 adjusting wheel rotatably fixed therewith; andcommon adjusting Wheel means in inter-engagement with said first namedadjusting wheel and said second named adjusting wheel to procureadjusting rotation of said control bevel gear and said control eccentricin opposite directions.

5. All the means as described and as claimed in claim 1 and incombination; means to rotate the said normally static control bevel gearon its axis and means to rotatethe said normally static controleccentric on its axis.

ADOLPHE C. PETERSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,449,129 Pescara Mar. 20, 1923 2,364,496 Vogel Dec. 5, 19442,414,435 Bendix Jan. 21, 1947 2,415,999 Frasher Feb, 8, 1947 2,506,210Goodson et al May 2, 1950 FOREIGN PATENTS Number Country Date 10,467Great Britain Nov. 18, 1909 610,434 Germany Mar. 12, 1935

